There are many cases where a vendor will tell you
that with each new upgrade of the operating system
one does not need to wipe the disk clean.
Whenever possible, and given the chance, wipe
clean the system disk with a "newfs" or "mkfs",
depending on your unix flavor.
If a version number leaps an entire number
for example, Version 5.3 -> version 6.2, it
is highly recommended that the disk be wiped
clean. In some cases it can be safe to
upgrade without wiping a system disk if the
version is not a full leap for example,
Version 5.2 -> Versions 5.3
Past history has shown that in some cases the
following could happen if a system disk wasn't
wiped clean first:
1) New versions mixed with older patches can
cause the system to become unstable.
2) Old configuration files are not compatible with
the newer O.S.
3) Some 3rd party software or device drivers wouldn't
4) Loss of unknown modified system files.
5) The new kernel will not be able to compile sometimes.
NOTE: All tips provided are USE AT YOUR OWN RISK. Tips are submitted
by various unix admins around the globe. UGU suggest you read and
test each tip in a non-volitile environment before placing into